Chromodoris obsoleta from Saudi Arabia

Dear George,

This is an interesting find. They do look quite like C. lekker, but the gills are 'bushier' and branched, and have a white line along the edges, while in C. lekker the gills are much simpler with a white band up the inner core of each gill. Also the rhinophores are edged in white while in C. lekker the individual leaflets on each rhinophore are smaller and are not lined with white.

Your animal is Chromodoris obsoleta which seems to be restricted to the northwestern corner of the Indian Ocean. In your photo the dark purplish black reminds me very much of a sponge of similar colour. If this species is quite common it woud be nice to confir what this species eats so if you could possibly take a close-up photo of the sponge  would be grateful. As you will see from other comments of mine I am very keen to know what what these animals 'do' so if you by change see one laying an egg ribbon a photo would be very welcome.

Also, we know very little about nudibranchs in this part of the world so photos of your finds would also be welcome. It would also be valuable to check the off-white chromodorids you find because it is possible that your have more than one species present. I can't really say how one species differs on colour from another, because in many cases two or three species may look very similar to each other, so I guess the best advice I can give you is to look out for differences, Even if you send me photos of three animals which look different to you but are the same species, it doesn't really matter as it will give us a better idea of colour variation in the species.

Best wishes,
Bill Rudman